This invention relates to measuring radiation and, more particularly, to a semiconductor device for measuring low-level doses of ionizing radiation.
In a number of medical, military and other applications, it is important to be able to measure the dose of ionizing radiation to which an animate or inanimate object is exposed. Ideally, the instrumentality utilized to measure dosage should be low in cost, reliable and sensitive.
Detecting radiation at low levels (for example, radiation in the range of 10-to-100 rads) requires a particularly sensitive device. (A rad is a unit of radiation dose equal to the quantity of ionizing radiation that results in the absorption of 100 ergs of energy per gram of irradiated material.)
Devices of the metal-oxide-semiconductor (MOS) type have been suggested for use as radiation detectors. But, heretofore, in practice the sensitivity of such devices has generally been insufficient to enable them to be employed as effective radiation detectors in the aforespecified low-level range.